1. Field of the Invention
This invention relates to poly(arylene sulfide)-poly(phenylene ether) resin compositions, and more particularly relates to compatibilized poly(arylene sulfide)-poly(phenylene ether) resin compositions and methods for preparation thereof.
2. Description of the Related Art
The poly(phenylene ether) resins are a widely used class of thermoplastic engineering resins characterized by excellent hydrolytic stability, dimensional stability, toughness, heat resistance and dielectric properties. However, they are deficient in certain other properties such as solvent resistance.
For their part, poly(arylene sulfide)s are crystalline engineering thermoplastics with high crystalline melting temperatures, typically on the order of 285.degree. C., and are characterized by low flammability, high modulus and excellent resistance to aggressive chemicals and solvents. However, their glass transition temperatures are very low, typically as low as 85.degree. C.; as a consequence, heat distortion temperatures are low in the absence of reinforcement with fillers such as glass fiber. In addition, poly(arylene sulfide) resins are very brittle, as evidenced by a tensile elongation to break for poly(phenylene sulfide) which is usually no greater than about 2.5% and frequently below 1%.
It might be expected that blends containing poly(arylene sulfide)-poly(phenylene ether) resins could be prepared which would have such properties as high solvent resistance, high heat distortion temperature, good ductility and resistance to flammability. However, blends of this type are incompatible and undergo phase separation and delamination, as a result of little or no phase interaction between the two resin phases. Molded parts made from such blends are typically characterized by low tensile and impact strength.
Compatible poly(arylene sulfide)/poly(phenylene ether) resin compositions have been prepared by melt compounding of an epoxy triazine capped poly(phenylene ether) resin with a poly(arylene sulfide) containing epoxide reactive functional groups (see Han et al., U.S. Pat. No. 5,122,578, which is included herein by reference). Utilization of epoxy functionalized poly(phenylene ether) resin, however, has certain disadvantages associated with it, including that solution processes for formation of the epoxy functionalized poly(phenylene ether) resin can be expensive, and as set out in Khouri et al., U.S. Pat. No. 5,132,373, the use of epoxy chlorotriazines as capping agents has certain disadvantages including: the necessity to use compounds such as glycidol in the preparation of the epoxy chlorotriazines, wherein the glycidol is expensive and also has carcinogenic properties. Khouri et al., U.S. Pat. No. 5,132,373 sets out ortho ester capped poly(phenylene ether) resins and methods for preparation thereof, and is included herein by reference. Khouri et al., U.S. Pat. No. 5,212,255 sets out ortho ester grafted poly(phenylene ether) resins and methods for preparation thereof, and is included herein by reference.
Accordingly, the object of the present invention is to provide poly(arylene sulfide) resin/poly(phenylene ether) resin compositions which exhibit desired levels of impact strength, tensile strength and tensile elongation.